UNDER THE SPELL OF VOLCANOES : Atop a caldera, checking in at Oregon's refurbished Crater Lake Lodge

CRATER LAKE, Ore. — Next to Oregon's most famous hole in the ground stands a landmark that may be the state's most beloved bad idea.

The hole is Crater Lake. For thousands of years, its deep blue waters have collected in the eerily round cup of a blown-out volcano. Its altitude--7,000 feet at the rim's edge--means that it is bordered by stands of pine and blanketed in snow for most of the year. It is the epicenter of Oregon's only national park.

The bad idea would be the Crater Lake Lodge.

Now, don't take that the wrong way. The hotel, which reopened May 20 after six years idle, is handsome, rough-hewn and positioned to offer staggering views of the lake in its caldera below. But from its beginnings 80 years ago, the idea of a hotel that would open for four months and spend the rest of the year empty and snowbound--a building raised without a proper foundation on the edge of a famously steep cliff--well, it seemed a little shaky. And so it was, a four-story beast of wood and stone with a back patio that tended to crumble under certain tonnages of snow.

But as it endured, through warnings and crumblings and entire decades of dubious safety conditions, the lodge apparently won the nostalgic affection of all Oregon. At least, enough of Oregon loved the place, and wrote the authorities to say so, that today, 11 years after the National Park Service announced plans to kill it, it's been reborn.

Since its closure amid dire cautions in 1989, the lodge has been firmed and polished by a $15-million rebuilding effort that added a new foundation, basement and steel skeleton to the building. Instead of 150 small rooms, many without baths, it now counts 71, each with bath and toilet (although there are eight without showers).

It matters little that the National Park Service's historian on the scene, Stephen R. Mark, dismisses the lodge as "a bad example of rustic architecture." Before the first week of the lodge's new life was over, each of those 71 rooms was sold out for the months of July and August, and the phone company was telling hotel officials that their reservation system, designed to accommodate 50 calls per hour, was getting twice that many. In fact, as the summer of '95 began, it seemed that all up and down the American West, travelers were thinking fond, nostalgic thoughts of Crater Lake and that four-story beast on top of the cliff. I reached the scene on May 22, using the standard approach. Flew to San Francisco, connected to Medford. Then I drove 75 miles northeast on Oregon 62, through great green forests along the Upper Rogue River, and for the last dozen miles crawled up the well-plowed mountain road as the snow deepened all around.

At last, there it was: the round, blue lake, the surrounding pines, the beloved lodge, the tall snow. It's a surreal landscape, so striking that even I, a man who doesn't know how his own car works, or his microwave, or his television, was compelled to sit still for a brief science lesson from a park service interpretive publication. This is the short version:

Once, in the land we now know as southern Oregon, there stood a volcano, which we now know as Mt. Mazama. It was about 12,000 feet high, neighbored by glaciers, forced upward by volcanic pressure below. About 6,850 years ago (so say the carbon-dating specialists, looking at trees turned to charcoal), it blew. This was a big eruption, sending more than 50 cubic kilometers of magma into the atmosphere--that is, more than 150 times as much magma as was ejected in 1980 by Mt. St. Helens.

When the ash settled, the mountain was a ghost and in its place lay a caldera 4,000 feet deep, surrounded by cliffs, about 20 miles in circumference. Snow and rain collected. Eventually, despite the epic snows of winter--about 430 inches a year over the last five--the lake in the crater settled at its current depth of 1,932 feet. Hence the lake's relatively stable water temperature (its skin may freeze in parts, but its depths remain at 38 degrees), and the odd blue hue of the water.

If you visit in winter, well, you're a hardy visitor indeed. From October to May, there is no boat tour and no rim road. The lodge is closed, although the Rim Village cafeteria and gift shop do stay open. Mostly, the park in those months is a 183,000-acre haven of well-flocked conifers and two-story snowpacks.